Power semiconductor switching devices are either normally-on devices conducting a load current in the absence of a potential difference between gate and source or normally-off devices which do not conduct a load current in the absence of a potential difference between gate and source. Inter alia for safety reasons normally-off switching devices are more popular. On the other hand in some applications, such as cascode circuits, normally-on switching semiconductor devices can reduce circuit complexity.
Further in the field of power semiconductor switching devices a desaturation cycle may partly reduce a charge carrier plasma before switching the semiconductor switching device from an on-state to a blocking state.